The present invention relates to an electrically insulating crosslinkable thin-film-forming organic resin composition and to a method for forming an electrically insulating crosslinkable thin film. More particularly, it relates to an electrically insulating crosslinked thin-film-forming organic resin composition from which it is possible to form a crosslinkable thin film having good heat resistance and low dielectric constant and excellent adhesion to the surface of electronic devices, and to a method for efficiently forming on the surface of an electronic device a thin film having good heat resistance and low dielectric constant and excellent adhesion to the surface.
Examples of a method for forming an electrically insulating crosslinked thin film on the surface of an electronic device include a method in which the surface of an electronic device is coated with a hydrogen silsesquioxane resin solution, the solvent is evaporated off, and the surface is then heated at 150 to 1000xc2x0 C. (see Japanese Laid-Open Patent Application S63-144525), and a method in which the surface of an electronic device is coated with a solution of a hydrogen silsesquioxane resin and a platinum or rhodium catalyst, the solvent is evaporated off, and the surface is then heated at 150 to 1000xc2x0 C. (see Japanese Laid-Open Patent Application S63-144524).
As miniaturization and integration have increased in electronic devices in recent years, there has been a need for a method for forming an electrically insulating layer with a low dielectric constant. More specifically, there is a need for a method for forming an electrically insulating layer with a low dielectric constant (a specific inductive capacity of less than 2.5) in a highly integrated circuit with a next-generation design rule of 0.15 xcexcm or less. Accordingly, Japanese Laid-Open Patent Application H10-279687 proposes a method in which the surface of an electronic device is coated with a solution composed of a hydrogen silsesquioxane resin and two types of solvent with different boiling points or affinity to this resin, after which part of the solvent is evaporated, and the surface is heated to evaporate the solvent either during or after the crosslinking of the resin, thereby forming a porous electrically insulating crosslinked thin film.
However, a porous electrically insulating crosslinked thin film generally has poor mechanical strength and is susceptible to infiltration and attack by a variety of chemicals, and therefore cannot sufficiently stand up to next-generation multilayer wiring processes, and particularly a copper dual damascene process, therefore making such films impractical. Also, to form an electrically insulating crosslinked thin film with a low dielectric constant, a relatively large amount of silicon atom-bonded hydrogen atoms must be present in the hydrogen silsesquioxane resin, and consequently the silicon atom-bonded hydrogen atoms in the thin film react due to the heat, various chemicals, or plasma encountered in the various steps following the formation of the thin film, such as the multilayer wiring of an electronic device, which further raises the density of the thin film and drives up the dielectric constant.
There have also been numerous proposals for electrically insulating crosslinkable thin-film-forming organic resin compositions that form electrically insulating thin films with a relatively low dielectric constant, but the problem with these electrically insulating thin films is their poor heat resistance and when they are heated to over 400xc2x0 C. in the course of manufacturing an electronic device there is a decrease in the film quality or quantity. Furthermore, such electrically insulating thin films have inferior adhesion to electronic device surfaces and peel off during the manufacturing of such an electronic device.
Specifically, it is an object of the present invention to provide an electrically insulating crosslinkable thin-film-forming organic resin composition from which it is possible to form a crosslinked thin film having good heat resistance and low dielectric constant and excellent adhesion to the surface of electronic devices, and to a method for efficiently forming on an electronic device surface an electrically insulating crosslinked thin film having good heat resistance and low dielectric constant and excellent adhesion to the surface of electronic devices.
The present invention is an electrically insulating crosslinkable thin-film-forming organic resin composition comprising (A) an electrically insulating organic resin having silicon atom-bonded hydrogen atoms or silicon atom-bonded alkenyl groups and (B) a solvent, and a method for forming a crosslinked thin film therefrom.